Macrophage characteristics expressed in monocytes in ICU patients

Abstract

Introduction: Patients presenting in the intensive care unit with severe injury or infections, typically carry a substantial inflammatory cytokine burden. The pathophysiological changes to leukocytes are poorly defined in these patients. This study aims to look at the macrophage-like characteristics of monocytes in patients entering into the ICU with severe inflammation / sepsis. Methods: The study has been approved by ”Regional committee for Medical and Health Research Ethics North(REC north). Monocytes were investigated using flow cytometry (FACS analysis) and fluorescence microscopy. For the FACS analysis, 11 healthy adult volunteers and 6 patients were recruited. For the fluorescence microscopy, 1 healthy volunteer and 1 patient were recruited. Results: The results from the FACS analysis were difficult to interpret, but might suggest that the monocytes from the patient populations have either become highly stressed and are changing morphology, and or, they are rapidly changing morphology and phenotype. The fluorescence microscopy results suggest that this analysis may give a better indication on the changes in monocytes compared to the FACS analyses. Conclusion: This project has provided an insight into specialist clinical and research areas. It has been an interesting journey to find better ways to understand the patient condition and, hopefully, look at possibilities to eventually improve treatment plans and protocols. Data from an ICU patient revealed marked present changes in their monocytes in a short time frame. These cells might be able to facilitate an understanding of macrophage priming for further differentiation in the future.